This invention relates generally to electronic coupled in motion railroad track scales. More specifically, this invention relates to an electronic coupled-in-motion railroad track scale with a track switch configuration having connected thereto logic electronics which permits the determination of the axle direction and which simultaneously tracks individual cars by counting the axles.
Switch systems for axle direction determination and other purposes such as speed measurement and car size discrimination heretofore have been proposed. In the patent to E. L. Rogers, U.S. Pat. No. 3,406,771, a system using two movable contact switches, and two switches composed of insulated section of rail that are electronically shorted by the wheels of the train and are located just off the weighbridge, is disclosed. Each contact switch is placed approximately six feet from one of the insulated section of rail switches, wherefore the first pair work in conjunction with each other to discriminate between locomotives and rail cars, while the latter pair are utilized to determined overspeed problems.
Tonies et al., U.S. Pat. No. 3,646,327, discloses a method detecting axle and readout synchronism which uses four axle detectors spaced evenly from one another, with three of the detectors on the approach track and one of the detectors on the weigh rail. The first and last detectors are used to record the count totals of axles moving past one or the other detectors along the line of movement of the train. The inner detectors have no counters associated with them but are used to indicate movement.
The in-motion car weighing system disclosed by Johnson et al. in U.S. Pat. No. 4,134,464 includes two sets of load cells and three wheel sensing devices. The wheel sensing devices are used in conjunction with the load cells to provide, in a bidirectinal weighing mode, axle counts and a locomotive car discriminating capacity. Thus, the load cells serve a double duty of determining weight and detecting axles.
While car size discrimination, axle counting and direction determination and other important in-motion weighing system functions have been provided by the prior art, the prior art has not provided a simple, inexpensive, accurate, and reliable system such as that of the present invention.